tests: Disable for rhg remaining tests that fail in that mode
These cases are in features not yet implemented by rhg
for which triggering a fallback is not practical.
Disabling some tests allows us to reach passing CI and catch
any future regression in the rest of the tests.
Differential Revision: https://phab.mercurial-scm.org/D10190
#require docutils gettext
$ $TESTDIR/check-gendoc fr
checking for parse errors